Abstract: Conventional flexible plate coupling works unsatisfactorily under high speed and dynamic load conditions,such as in high speed single cylinder motorcycle engine test bed.In the paper,failure phenomena of pin driving flexible plate coupling was studied experimentally.Effects of construction of coupling,size and material of flexible plate on service life of coupling were investigated in detail.A clamping ring type flexible plate coupling was developed which was characterized by smooth,endurable work and being tolerant of radial and axial offset.Tested with a high speed and dynamic load single cylinder gasoline engine,developed coupling with clamping ring showed more than 4 times as much life span as it without clamping ring.

Key words: flexible-plate coupling, life-span, test-bed